Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 11, 2014 at 04:40 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update July 1, 2014)] [Cycle 24 progress (last update July 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update July 1, 2014)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update July 1, 2014)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update July 5, 2014)]

[POES auroral activity level October 2009 - December 2012]
[Solar polar fields vs solar cycles - updated June 4, 2014]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]

Recent activity

The geomagnetic field was quiet to unsettled on July 10. Solar wind speed at SOHO ranged between 349 and 396 km/s, likely under the influence of a low speed stream from CH626.

Solar flux at 20h UTC on 2.8 GHz was 177.4 (increasing 24.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 139.7. The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.4). Three hour interval K indices: 32211112 (planetary), 33413322 (Boulder).

The background x-ray flux is at the class C1 level.

At the time of counting spots (see image time), spots were observed in 12 active regions using 2K resolution (SN: 288) and 10 active regions using 1K resolution (SN: 189) SDO images on the visible solar disk.

Region 12104 [S12W80] decayed slowly and quietly.
Region 12106 [N14W75] decayed quickly and was somewhat unstable.
Region 12107 [S19W67] decayed slowly and quietly.
Region 12108 [S07W52] decayed slowly and was quiet. An M class flare is possible.
Region 12109 [S08W33] decayed slowly and displayed no significant activity.
Region 12111 [N05W16] gained a few spots and was quiet.
Region 12113 [N08E24] gained spots and could produce C and minor M class flares.
Region 12114 [S20E39] displayed no major changes and was quiet.
New region 12116 [S28E44] emerged on July 8 and was numbered by SWPC 2 days later.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3622 [S22W08] was quiet and stable.
New region S3634 [S05W45] emerged near AR 12108.
New region S3635 [S21W32] was observed with a penumbra spot.

C2+ Flares (GOES):

Magnitude Peak time (UTC) Location AR
C5.7/1N 02:53 N17W65 12106
C7.4 21:13   12113
M1.5 22:34   12106

Coronal mass ejections (CMEs)

July 8: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.
July 9: A partial halo CME was observed after the M1 flare in AR 12113. There is a minor chance that a weak extension could reach Earth on July 12.
July 10: A partial halo CME was observed after a filament eruption near the southwest limb. The CME has only a minor chance of causing geomagnetic effects.

Coronal holes

Coronal hole history (since October 2002)
Compare today's report to the situation one solar rotation ago: 28 days ago 27 days ago 26 days ago

A trans equatorial coronal hole (CH626) was in an Earth facing position on July 5.

Coronal hole map

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle latitudes is poor. Propagation on long distance northeast-southwest paths is poor to fair.

Forecast

The geomagnetic field is expected to be quiet on July 11-13 quiet conditions are likely. There is a slight chance of CME effects on July 12-13.

Coronal holes (1) Coronal mass ejection (2) M and X class flares (3)
     

1) Effects from a coronal hole could reach Earth within the next 5 days. When the high speed stream has arrived the color changes to green.
2) Effects from a CME are likely to be observed at Earth within 96 hours.
3) There is a possibility of either M or X class flares within the next 48 hours.

Green: 0-30% probability, Yellow: 30-70% probability, Red: 70-100% probability.

Active solar regions

(Click on image for 2K resolution) Compare to the previous day's image. 0.5K image

When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue is positive.

Data for all numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC. Comments are my own, as is the STAR spot count (spots observed at or inside a few hours before midnight) and data for regions not numbered by SWPC or where SWPC has observed no spots. SWPC active region numbers in the table below and in the active region map above are the historic SWPC/USAF numbers.

Active region Date numbered
detected
Spot count Location at midnight Area Classification SDO / HMI 4K continuum
image with magnetic polarity overlay
Comment
SWPC Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
12104 2014.06.28 2 2 2 S11W80 0070 DSO DSO  
12107 2014.06.28
2014.06.29
1 4 2 S18W68 0150 HAX CSO  

area: 0240

12106 2014.06.29 2 4 3 N16W75 0060 CAO AXX  
12108 2014.06.30
2014.07.01
14 30 14 S07W52 0690 EKC EKC beta-gamma
12109 2014.07.01
2014.07.02
17 34 16 S08W33 0600 DKC DKC beta-gamma
12110 2014.07.02
2014.07.03
      S15W47           plage
12111 2014.07.03
2014.07.04
8 28 16 N05W16 0080 DSI DAI  
S3614 2014.07.04       N06W05           plage
S3618 2014.07.05       N18W12         plage
12113 2014.07.06 6 23 17 N09E20 0060 DAI DAI

location: N08E24

12115 2014.07.06
2014.07.08
2     N08W63 0010 AXX     spotless
S3622 2014.07.06   2   S22W08 0004   BXO images/AR_S3622_20140709_2345.png   
S3623 2014.07.06       S18W26           plage
S3627 2014.07.06       N10W55           plage
12114 2014.07.07
2014.07.08
4 23 10 S20E39 0070 DAO CAO  
12116 2014.07.08
2014.07.10
3 11 5 S28E43 0020 BXO DRO  
S3631 2014.07.08       S15E36           plage
S3632 2014.07.08       S16E02           plage
S3633 2014.07.08       N15E07           plage
S3634 2014.07.10   6 4 S05W45 0030   DRO    
S3635 2014.07.10   1   S21W32 0002   AXX    
Total spot count: 59 168 89  
Sunspot number: 159 288 189  (total spot count + 10 * number of spotted regions)
Weighted SN: 109 219 140  (Sum of total spot count + classification weighting for each AR. Classification weighting: X=0, R=3, A/S=5, H/K=10)
Relative sunspot number (Wolf number): 95 101 104 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for MSN 2K, k = 0.55 for MSN 1K (MSN=Magnetic Sunspot Number)

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO)
Smoothed sunspot number Average ap
(3)
Measured 1 AU
2013.02 104.3 101.8 38.0 58.4 (-0.3) 6.11
2013.03 111.3 110.2 57.9 57.5 (-0.9) 10.56
2013.04 124.8 125.9 72.4 57.9 (+0.4) 5.40
2013.05 131.4 134.3 78.7 59.9 (+2.0) 9.73
2013.06 110.1 113.7 52.5 62.6 (+2.7) 12.60
2013.07 115.5 119.3 57.0 65.5 (+2.9) 9.47
2013.08 114.6 118.3 66.0 69.0 (+3.5) 8.27
2013.09 102.6 103.7 36.9 73.1 (+4.1) 5.23
2013.10  132.1 131.2 85.6 75.0 (+1.9) 7.71
2013.11  148.3 145.1 77.6 75.4 (+0.4) 5.68
2013.12 147.7 143.1 90.3 76.0 (+0.6) 4.68
2014.01 157.4 152.4 81.8 (78.2 projected, +2.2) 5.44
2014.02 170.3
(cycle peak)
166.3 102.3 (cycle peak) (79.7 projected, +1.5) 10.70
2014.03 149.9 148.5 91.9 (80.5 projected, +0.8) 4.88
2014.04 143.9 144.8 84.7 (79.7 projected, -0.8) 7.88
2014.05 129.7 132.9 75.2 (77.1 projected, -2.6) 5.75
2014.06 122.0 125.8 71.0 (74.5 projected, -2.6) 6.72
2014.07 185.6 (1)   62.2 (2A) / 192.7 (2B) / 99.0 (2C) (71.5 projected, -3.0) (4.9)

1) Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz.
2A) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days). The official WDC-SILSO international sunspot number is typically 30-50% lower. 2B) Boulder SN current month average to date. 2C) STAR SDO 1K Wolf number 30 day average.
3) Running average based on the quicklook and definitive Potsdam WDC ap indices. Values in red are based on the definitive international GFZ Potsdam WDC ap indices.

This report has been prepared by Jan Alvestad. It is based on the analysis of data from whatever sources are available at the time the report is prepared. All time references are to the UTC day. Comments and suggestions are always welcome.

SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.